There are three unique situations:
Margin="a,b,c,d"
.Margin="a,b"
.Margin="a"
.If there are 4 numbers, then its left
, top
, right
, bottom
(a clockwise circle starting from the middle left margin). First number is always the "West" like "WPF":
<object Margin="left,top,right,bottom"/>
Example: if we use Margin="10,20,30,40"
it generates:
If there are 2 numbers, then the first is left & right margin thickness, the second is top & bottom margin thickness. First number is always the "West" like "WPF":
<object Margin="a,b"/> // Equivalent to Margin="a,b,a,b".
Example: if we use Margin="10,30"
, the left & right margin are both 10, and the top & bottom are both 30.
If there is 1 number, then the number is repeated (its essentially a border thickness).
<object Margin="a"/> // Equivalent to Margin="a,a,a,a".
Example: if we use Margin="20"
it generates:
Have been working on a large-scale WPF application for the past 5 years with over 100 screens. Part of a team of 5 WPF/C#/Java devs. We eventually settled on either using 1 number (for border thickness) or 4 numbers. We never use 2. It is consistent, and seems to be a good way to reduce cognitive load when developing.
The rule:
All width numbers start on the left (the "West" like "WPF") and go clockwise (if two numbers, only go clockwise twice, then mirror the rest).